During my recent work on the rtnl lock deadlock in the IPoIB driver, I
saw that even once I fixed the apparent races for a single device, as
soon as that device had any children, new races popped up. It turns
out that this is because no matter how well we protect against races
on a single device, the fact that all devices use the same workqueue,
and flush_workqueue() flushes *everything* from that workqueue means
that we would also have to prevent all races between different devices
(for instance, ipoib_mcast_restart_task on interface ib0 can race with
ipoib_mcast_flush_dev on interface ib0.8002, resulting in a deadlock on
the rtnl_lock).
There are several possible solutions to this problem:
Make carrier_on_task and mcast_restart_task try to take the rtnl for
some set period of time and if they fail, then bail. This runs the
real risk of dropping work on the floor, which can end up being its
own separate kind of deadlock.
Set some global flag in the driver that says some device is in the
middle of going down, letting all tasks know to bail. Again, this can
drop work on the floor.
Or the method this patch attempts to use, which is when we bring an
interface up, create a workqueue specifically for that interface, so
that when we take it back down, we are flushing only those tasks
associated with our interface. In addition, keep the global
workqueue, but now limit it to only flush tasks. In this way, the
flush tasks can always flush the device specific work queues without
having deadlock issues.
Signed-off-by: Doug Ledford <dledford@redhat.com>
We blindly assume that we can just take the rtnl lock and that will
prevent races with downing this interface. Unfortunately, that's not
the case. In ipoib_mcast_stop_thread() we will call flush_workqueue()
in an attempt to clear out all remaining instances of ipoib_join_task.
But, since this task is put on the same workqueue as the join task,
the flush_workqueue waits on this thread too. But this thread is
deadlocked on the rtnl lock. The better thing here is to use trylock
and loop on that until we either get the lock or we see that
FLAG_OPER_UP has been cleared, in which case we don't need to do
anything anyway and we just return.
While investigating which flag should be used, FLAG_ADMIN_UP or
FLAG_OPER_UP, it was determined that FLAG_OPER_UP was the more
appropriate flag to use. However, there was a mix of these two flags in
use in the existing code. So while we check for that flag here as part
of this race fix, also cleanup the two places that had used the less
appropriate flag for their tests.
Signed-off-by: Doug Ledford <dledford@redhat.com>
The ipoib_mcast_flush_dev routine is called with the rtnl_lock held and
needs to keep it held. It also needs to call flush_workqueue() to flush
out any outstanding work. In the past, we've had to try and make sure
that we didn't flush out any outstanding join completions because they
also wanted to grab rtnl_lock() and that would deadlock. It turns out
that the only thing in the join completion handler that needs this lock
can be safely moved to our carrier_on_task, thereby reducing the
potential for the join completion code and the flush code to deadlock
against each other.
Signed-off-by: Doug Ledford <dledford@redhat.com>
In preparation for using per device work queues, we need to move the
start of the neighbor thread task to after ipoib_ib_dev_init and move
the destruction of the neighbor task to before ipoib_ib_dev_cleanup.
Otherwise we will end up freeing our workqueue with work possibly
still on it.
Signed-off-by: Doug Ledford <dledford@redhat.com>
Create a an ipoib_flush_ah and ipoib_stop_ah routines to use at
appropriate times to flush out all remaining ah entries before we shut
the device down.
Because neighbors and mcast entries can each have a reference on any
given ah, we must make sure to free all of those first before our ah
will actually have a 0 refcount and be able to be reaped.
This factoring is needed in preparation for having per-device work
queues. The original per-device workqueue code resulted in the following
error message:
<ibdev>: ib_dealloc_pd failed
That error was tracked down to this issue. With the changes to which
workqueues were flushed when, there were no flushes of the per device
workqueue after the last ah's were freed, resulting in an attempt to
dealloc the pd with outstanding resources still allocated. This code
puts the explicit flushes in the needed places to avoid that problem.
Signed-off-by: Doug Ledford <dledford@redhat.com>
Instead of calling target_fabric_configfs_init() +
target_fabric_configfs_register() / target_fabric_configfs_deregister()
target_fabric_configfs_free() from every target driver, rewrite the API
so that we have simple register/unregister functions that operate on
a const operations vector.
This patch also fixes a memory leak in several target drivers. Several
target drivers namely called target_fabric_configfs_deregister()
without calling target_fabric_configfs_free().
A large part of this patch is based on earlier changes from
Bart Van Assche <bart.vanassche@sandisk.com>.
(v2: Add a new TF_CIT_SETUP_DRV macro so that the core configfs code
can declare attributes as either core only or for drivers)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
These variables are always accessed via struct isert_conn so
no need to have a "conn_" prefix for them.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
iser target can handle as many connect request as
the fabric sends to it. This backlog should not set as
a back-pressure mechanism (which is not very useful).
isert does need a back-pressure mechanism, but it should
be added in isert by monitoring the number of pending
established connections (will be added in a later stage).
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
In iser_connect_release there is no chance that
the iser device is set to NULL, if this happens
we have a BUG. So use BUG_ON.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Not sure what it was used for, but there is
no real need for it now as I see it. Go ahead
and get rid of it.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Move login buffer alloc/free code to dedicated
routines and introduce isert_conn_init which
initializes the connection lists and locks.
Simplifies and cleans up the code a little bit.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
isert_device_find_by_ib_dev and isert_device_try_release
can have a better, more common name like isert_device_[get|put].
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
No need to keep a local ib_dev as a device pointer.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Move the code for completion context handling to dedicated
routines. This simplifies the code and removes code duplication.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Simplify iser QP creation by splitting some unrelated
logic bulks to routines.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This is to favor the HCA cache hit rate using less MRs
and PDs. This commit partially reverts commit:
"eb6ab13 IB/isert: separate connection protection domains and dma MRs"
At the time I thought this would be needed.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Before we reach to connection established we may get an
error event. In this case the core won't teardown this
connection (never established it), so we take care of freeing
it ourselves.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # v3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This hang was a result of a missing command put when
a DIF error occurred during a rdma read (and we sent
an CHECK_CONDITION error without passing it to the
backend).
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # v3.14+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Pull SCSI target updates from Nicholas Bellinger:
"The highlights this round include:
- Update vhost-scsi to support F_ANY_LAYOUT using mm/iov_iter.c
logic, and signal VERSION_1 support (MST + Viro + nab)
- Fix iscsi/iser-target to remove problematic active_ts_set usage
(Gavin Guo)
- Update iscsi/iser-target to support multi-sequence sendtargets
(Sagi)
- Fix original PR_APTPL_BUF_LEN 8k size limitation (Martin Svec)
- Add missing WRITE_SAME end-of-device sanity check (Bart)
- Check for LBA + sectors wrap-around in sbc_parse_cdb() (nab)
- Other various minor SPC/SBC compliance fixes based upon Ronnie
Sahlberg test suite (nab)"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (32 commits)
target: Set LBPWS10 bit in Logical Block Provisioning EVPD
target: Fail UNMAP when emulate_tpu=0
target: Fail WRITE_SAME w/ UNMAP=1 when emulate_tpws=0
target: Add sanity checks for DPO/FUA bit usage
target: Perform PROTECT sanity checks for WRITE_SAME
target: Fail I/O with PROTECT bit when protection is unsupported
target: Check for LBA + sectors wrap-around in sbc_parse_cdb
target: Add missing WRITE_SAME end-of-device sanity check
iscsi-target: Avoid IN_LOGOUT failure case for iser-target
target: Fix PR_APTPL_BUF_LEN buffer size limitation
iscsi-target: Drop problematic active_ts_list usage
iscsi/iser-target: Support multi-sequence sendtargets text response
iser-target: Remove duplicate function names
vhost/scsi: potential memory corruption
vhost/scsi: Global tcm_vhost -> vhost_scsi rename
vhost/scsi: Drop left-over scsi_tcq.h include
vhost/scsi: Set VIRTIO_F_ANY_LAYOUT + VIRTIO_F_VERSION_1 feature bits
vhost/scsi: Add ANY_LAYOUT support in vhost_scsi_handle_vq
vhost/scsi: Add ANY_LAYOUT iov -> sgl mapping prerequisites
vhost/scsi: Change vhost_scsi_map_to_sgl to accept iov ptr + len
...
In some cases, we might reach the iser connection termination without
ep_disconnect being invoked (for example if user-space daemon doesn't
exists. In this case, we need to free the iscsi endpoint when we
remove the iser connection.
Signed-off-by: Ariel Nahum <arieln@mellanox.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
When teardown process starts during live IO, we need to keep the
memory regions pool (frmr/fmr) until all in-flight tasks are properly
released, since each task may return a memory region to the pool. In
order to do this, we pass a destroy flag to iser_free_ib_conn_res to
indicate we can destroy the device and the memory regions
pool. iser_conn_release will pass it as true and also DEVICE_REMOVAL
event (we need to let the device to properly remove).
Also, Since we conditionally call iser_free_rx_descriptors,
remove the extra check on iser_conn->rx_descs.
Fixes: 5426b1711f ("IB/iser: Collapse cleanup and disconnect handlers")
Reported-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
We always unmap SGs with the same direction instead of unmapping
with the direction the mapping was done, fix that.
Fixes: 9a8b08fad2 ("IB/iser: Generalize iser_unmap_task_data and [...]")
Signed-off-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
In case sendtargets response is larger than initiator MRDSL, we
send a partial sendtargets response (setting F=0, C=1, TTT!=0xffffffff),
accept a consecutive empty text message and send the rest of the payload.
In case we are done, we set F=1, C=0, TTT=0xffffffff.
We do that by storing the sendtargets response bytes done under
the session.
This patch also makes iscsit_find_cmd_from_itt public for isert.
(Re-add cmd->maxcmdsn_inc and clear in iscsit_build_text_rsp - nab)
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
The macro isert_dbg already ensures that __func__ is part of the
output, so there's no reason to duplicate the function name in the
format string itself.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
if text message dlength is 0, don't allocate a buffer for it, pass
NULL to iscsit_process_text_cmd.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Bound workqueues might be too restrictive since they allow
only a single core per session for processing completions.
WQ_UNBOUND will allow bouncing to another CPU if the running
CPU is currently busy. Luckily, our workqueues are NUMA aware
and will first try to bounce within the same NUMA socket.
My measurements with NULL backend devices show that there is
no (noticeable) additional latency as a result of the change.
I'd expect even to gain performance when working with fast
devices that also allocate MSIX interrupt vectors.
While we're at it, make it WQ_HIGHPRI since processing
completions is really a high priority for performance.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Reported-by: Moussa Ba <moussaba@micron.com>
Signed-off-by: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This reverts commit afe1de664e.
The series of IPoIB bug fixes that went into 3.19-rc1 introduce
regressions, and after trying to sort things out, we decided to revert
to 3.18's IPoIB driver and get things right for 3.20.
Signed-off-by: Roland Dreier <roland@purestorage.com>
This reverts commit 67d7209e1f.
The series of IPoIB bug fixes that went into 3.19-rc1 introduce
regressions, and after trying to sort things out, we decided to revert
to 3.18's IPoIB driver and get things right for 3.20.
Signed-off-by: Roland Dreier <roland@purestorage.com>
This reverts commit 016d9fb25c.
The series of IPoIB bug fixes that went into 3.19-rc1 introduce
regressions, and after trying to sort things out, we decided to revert
to 3.18's IPoIB driver and get things right for 3.20.
Signed-off-by: Roland Dreier <roland@purestorage.com>
This reverts commit e5d1dcf1b0.
The series of IPoIB bug fixes that went into 3.19-rc1 introduce
regressions, and after trying to sort things out, we decided to revert
to 3.18's IPoIB driver and get things right for 3.20.
Signed-off-by: Roland Dreier <roland@purestorage.com>
This reverts commit 3bcce487fd.
The series of IPoIB bug fixes that went into 3.19-rc1 introduce
regressions, and after trying to sort things out, we decided to revert
to 3.18's IPoIB driver and get things right for 3.20.
Signed-off-by: Roland Dreier <roland@purestorage.com>
This reverts commit 5141861cd5.
The series of IPoIB bug fixes that went into 3.19-rc1 introduce
regressions, and after trying to sort things out, we decided to revert
to 3.18's IPoIB driver and get things right for 3.20.
Signed-off-by: Roland Dreier <roland@purestorage.com>
This reverts commit bb42a6dd02.
The series of IPoIB bug fixes that went into 3.19-rc1 introduce
regressions, and after trying to sort things out, we decided to revert
to 3.18's IPoIB driver and get things right for 3.20.
Signed-off-by: Roland Dreier <roland@purestorage.com>
This reverts commit ce347ab90e.
The series of IPoIB bug fixes that went into 3.19-rc1 introduce
regressions, and after trying to sort things out, we decided to revert
to 3.18's IPoIB driver and get things right for 3.20.
Signed-off-by: Roland Dreier <roland@purestorage.com>
This patch changes srpt_close_session() to properly use an unsigned long
for wait_for_completion_timeout()'s return value, and to update WARN_ON()
to only trigger for a zero return.
Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Pull SCSI update from James Bottomley:
"This is a much shorter set of patches that were on the go but didn't
make it in to the early pull request for the merge window. It's
really a set of bug fixes plus some final cleanup work on the new tag
queue API"
* tag 'scsi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
storvsc: ring buffer failures may result in I/O freeze
ipr: set scsi_level correctly for disk arrays
ipr: add support for async scanning to speed up boot
scsi_debug: fix missing "break;" in SDEBUG_UA_CAPACITY_CHANGED case
scsi_debug: take sdebug_host_list_lock when changing capacity
scsi_debug: improve driver description in Kconfig
scsi_debug: fix compare and write errors
qla2xxx: fix race in handling rport deletion during recovery causes panic
scsi: blacklist RSOC for Microsoft iSCSI target devices
scsi: fix random memory corruption with scsi-mq + T10 PI
Revert "[SCSI] mpt3sas: Remove phys on topology change"
Revert "[SCSI] mpt2sas: Remove phys on topology change."
esas2r: Correct typos of "validate" in a comment
fc: FCP_PTA_SIMPLE is 0
ibmvfc: remove unused tag variable
scsi: remove MSG_*_TAG defines
scsi: remove scsi_set_tag_type
scsi: remove scsi_get_tag_type
scsi: never drop to untagged mode during queue ramp down
scsi: remove ->change_queue_type method
Pull SCSI target fixes from Nicholas Bellinger:
"The highlights this merge window include:
- Allow target fabric drivers to function as built-in. (Roland)
- Fix tcm_loop multi-TPG endpoint nexus bug. (Hannes)
- Move per device config_item_type into se_subsystem_api, allowing
configfs attributes to be defined at module_init time. (Jerome +
nab)
- Convert existing IBLOCK/FILEIO/RAMDISK/PSCSI/TCMU drivers to use
external configfs attributes. (nab)
- A number of iser-target fixes related to active session + network
portal shutdown stability during extended stress testing. (Sagi +
Slava)
- Dynamic allocation of T10-PI contexts for iser-target, fixing a
potentially bogus iscsi_np->tpg_np pointer reference in >= v3.14
code. (Sagi)
- iser-target performance + scalability improvements. (Sagi)
- Fixes for SPC-4 Persistent Reservation AllRegistrants spec
compliance. (Ilias + James + nab)
- Avoid potential short kern_sendmsg() in iscsi-target for now until
Al's conversion to use msghdr iteration is merged post -rc1.
(Viro)
Also, Sagi has requested a number of iser-target patches (9) that
address stability issues he's encountered during extended stress
testing be considered for v3.10.y + v3.14.y code. Given the amount of
LOC involved, it will certainly require extra backporting effort.
Apologies in advance to Greg-KH & Co on this. Sagi and I will be
working post-merge to ensure they each get applied correctly"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (53 commits)
target: Allow AllRegistrants to re-RESERVE existing reservation
uapi/linux/target_core_user.h: fix headers_install.sh badness
iscsi-target: Fail connection on short sendmsg writes
iscsi-target: nullify session in failed login sequence
target: Avoid dropping AllRegistrants reservation during unregister
target: Fix R_HOLDER bit usage for AllRegistrants
iscsi-target: Drop left-over bogus iscsi_np->tpg_np
iser-target: Fix wc->wr_id cast warning
iser-target: Remove code duplication
iser-target: Adjust log levels and prettify some prints
iser-target: Use debug_level parameter to control logging level
iser-target: Fix logout sequence
iser-target: Don't wait for session commands from completion context
iser-target: Reduce CQ lock contention by batch polling
iser-target: Introduce isert_poll_budget
iser-target: Remove an atomic operation from the IO path
iser-target: Remove redundant call to isert_conn_terminate
iser-target: Use single CQ for TX and RX
iser-target: Centralize completion elements to a context
iser-target: Cast wr_id with uintptr_t instead of unsinged long
...
In case the last argument of the connection string is processed as a
string (destination GID for example).
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Acked-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
